After the Union regained control of the Mississippi River in the summer of 1863, President Lincoln ordered the commander of the Department of the Gulf, Major General Nathaniel P. Banks, to "Plant the Flag in Texas." To assist in this endeavor, the XIII Corps was transferred to Banks' department. This brought Private William A. McMillan of the 67th Indiana to Louisiana. McMillan's diary, which covers the period from late December 1863 through the end of 1864, describes his participation in the occupation of the coast of Texas, the Red River Campaign, the capture of the forts guarding the entrance to Mobile Bay, and actions in Louisiana and Arkansas.